For a semiconductor device using silicon carbide (SiC), high temperature annealing is required in the manufacturing process thereof. However, it is found that when high temperature annealing is performed, the number of carbon vacancies in which carbon is deficient is necessarily increased in the silicon carbide. The carbon vacancy has the property of capturing minority carriers and thus reduces the lifetime of the minority carriers flowing in an element. Accordingly, the on-resistance of the device is raised in some cases. Therefore, in the semiconductor device using silicon carbide, it is desirable to decrease the number of carbon vacancies as much as possible.